Method of making protected piling



June 15, 1937. J, w, BLACKMAN 2,083,593

METHOD OF MAKING PROTECTED FILING Original Filed Nov. 10, 1934 2Sheets-Sheet 1- fzwelz/br. dirk/21a B. Blackmail,

June 15, 1937. w BLACKMAN 2,083,593

METHOD OF MAKING PROTECTED FILING Original Filed Nov. 10, 1934 2Sheets-Shoat 2 lwaezz/ar.

Job? M 3. B/cmfmaw,

Patented June 15, 1937 UNITED STATES PATENT OFFICE Original applicationNovember 10, 1934, Serial Divided and this application July 22, 1935,Serial No. 32,513

5 Claims.

This invention has to do generally with protected concrete piling, andhas for its principal object to provide improved methods for castingprotected concrete piles that possess numerous advantages over pastmethods both from standpoints of convenience and facility in the pilecasting operation and also the strength and deterioration resistingqualities of the pile itself. The present application is a division ofmy copending application, Ser. No. 752,445, filed Nov. 10, 1934, onProtected piling and method for making same, which application now dealswith the pile construction itself. Attention is also directed to asecond copending divisional application, Ser. No. 32,512, filed on evendate herewith on Method of forming and extending driven piling, whichdeals with methods for protecting and extending driven piling.

The necessity has long been realized of rendering concrete piling immuneto attack and deterioration by the action of sea water, alkalies, acids,frost, marine insects and the like. One of the most generally used andsuccessful methods employed in the past has been to first cast the pileof concrete having sufficient porosity to be capable of impregnation toa substantial depth by waterproofing material, such as asphalt, tothenheat the pile to exclude air and other gases from the pores of theconcrete, and finally immerse it in a bath of hot asp-halt under suchconditions that the asphalt is drawn into the pores to impregnate theouter depth of the concrete. While this method of protecting piles hasbeen found fully successful, it involves a practical disadvantage byreason of the necessity for a fairly large and expensive plant to carryout the impregnating operations. For this and the further reason that asufiicient number of piles is not required on the average job to warrantbuilding an impregnating plant for that job, it has been customary tocast and impregnate the piles at a distant permanent plant, and then toship them to the place where they are to b-eused. It will be apparent,of course, that because of the great size and weight of the averageconcrete pile, handling and shipping involve considerable expense,particularly where the piles must be transported long distances and toplaces not conveniently accessible.

One of the outstanding advantages of the in vention. is that it providesa method whereby prc.- tected concrete piles may be cast on the job, atthe place where they are to be driven, thus eliminating the difficultiesand expense incident to transporting the completed piles. In addition,

the invention offers the further advantage of providing protectedconcrete piling which from structural standpoints, has greater strengthand greater immunity from attack by the various agencies mentionedabove, than any type of concrete piling heretofore proposed.

The present pile structure may be described briefly as one in which theconcrete body of the pile is protected by a layer of slabs made ofmaterial that is fully resistant to attack and disintegration, withjoints between the slabs of an equally resistant character, so that theslabs together form a continuous protective layer at the surface of theconcrete. Preferably the slabs will be made of porous, asphaltimpregnated concrete, and will be cast and impregnated at a centralplant and shipped out to the jobs. By reason of their small size andlight weight, however, the slabs may be handled and transported atcomparatively low cost; and in a single shipment, sufficient slabs maybe transported to protect a large number of piles.

Two different methods may be used in applying the slabs to the pile. Inaccordance with one method, the slabs are first arranged as a permanentform into which the body or concrete core of the pile is cast, the slabshaving surface irregularities or key recesses into which the concreteflows, so that when the concrete sets, the slabs will have in effectbecome integrated with the body of the pile. In applying the slabs bythe sec ond method, the body of the pile is first cast, and the precastslabs applied and bonded to the body by grout poured into key recesseswithin both the slabs and the body. Both of these methods may be used informing different parts of the same pile, or the entire pile structuremay be cast in accordance with either one of the methods.

The advantages and desirable departures from past practice made possibleby the invention, include many additional features which would requireconsiderable space to set out at length. It is believed that a fullunderstanding of the objects and features mentioned above, as well asall the additional aspects and details of the invention, can mostreadily be given by proceeding directly to a description of certaintypical and illustrative embodiments of the invention. For this purposereference is had to the accompanying drawings, in which:

Fig. 1 is a perspective showing the arrangement of form slabs and bracesused in casting the pile, some of the slabs being removed to show moreclearly their shapes and relative positions;

Fig. 2 is a transverse sectional View showing the slabs and braces inthe aspect of Fig. 1, after the slab form has been filled with concrete;

Fig. 3 is a perspective showing the cast pile after removal from thestuds;

Fig. t is a fragmentary section taken in the vertical plane of line ilof Fig. 3;

Fig. 5 is a plan of one of the top slabs in Figs. 1 and 2, inverted toshow the key recesses;

Fig. 6 is a section on line 55-45 of Fig. 5;

Fig. 7 is a view, partly in section, showing the top portion of a drivenpile supporting a floor structure and having subsequently appliedprotective slabs keyed to its upper extent;

Fig. 8 is an enlarged section on line 8--8 of Fig. 7;

Fig. 9 is a front elevational View showing the protective slabs appliedto sheet piling;

Fig. 10 a vertical section on line Iii-16 of Fig. 9;

Fig. 11 is a horizontal section on line ll-H of Fig. 9;'

Fig. 12 is an elevation showing a further variational form of theinvention; and

Fig. 13 is an enlarged section on line iii-l3 of Fig. 12.

The form of the invention shown in Figs. 1 to 8 inclusive may best beexplained by first describing the method whereby a section of the pileis cast in a form composed of protective slabs, and then the procedurefollowed in applying slabs to the top portion of the pile after thelatter has been driven. Reference is first made to Figs. 1 and 2 for thepurpose of describing the sequence of operations in building up the slabform and finally filling it with concrete in casting the intermediatesection of the pile. First I lay a suitable platform if] on which iserected a series of brace structures ll comprising uprights i2, crosspieces i3 and diagonal braces i=3. A series of bottom slabs l5 are thenlaid end to end upon the platform [0, and two courses of slabs it placedupon the bottom diagonal braces M- with their inner edges engaging slabsi5. 1 have shown the angularly placed slab-s if: each to have twoelongated key recesses 15a with undercut sides and ends for the purposeof illustrating that if desired, not only the ends but the sides of theslab recesses may be undercut.

Fig. 5 illustrates the shape of the bottom slabs I5, as well as those inthe top course hereinafter described, although the latter are providedwith certain openings not present in the bottom slabs, as will laterappear. It may be stated first that all the slabs will be precast andformed of a suitable waterproof material or composition resistant toattack and disintegration by acids, alkalies, and other deterioratingagencies. Preferably the slabs are made of concrete impregnated withwaterproofing material such as asphalt, the concrete having sufficientporosity to 'be thoroughly impregnated throughout the interior of theslab. In this connection, reference is made to my c0- pendingapplication on Protective slabs for concrete, Ser. No. 667,251, filedApr. 21, 1933, for a more complete description of the advantages andcharacteristics of slabs of this general type. It will sufiice toobserve here that the slabs may be made of any suitable waterproofingmaterial resistant to deterioration, though I find asphalt impregnatedconcrete to be particularly well suited for my purposes.

Each slab i5 is rectangular in shape, of substantially uniformthickness, and has one or more key recesses l'l, three here being shownas typical, having undercut or dove-tailed ends [8, and

sides l9 which are beveled inwardly toward the base of the recesses. Aswill later appear, these recesses serve to form keys which securely bondthe slab to the concrete body of the pile. The recesses are entirelycontained within the slab so that the joint edges beyond the recessesare of the full thickness of the slab. In impregnating the slabs, thelatter are immersed for a time in a bath of hot asphalt and then removedwhen the asphalt has fully permeated the pores. The impregnated slabsare stood on end to cool and dry, and in order to insure completedrainage of asphalt from the key recesses I1, I cast drain notches Ila.within the undercut ends it of the recesses.

As shown in Fig. 2, the adjoining edges of slabs l5 and R6 are beveledto provide upwardly opening wedge-shaped joint spaces 29. Similarlyshaped joint spaces are formed at the ends of the slabs, correspondingto the later described joints illustrated in Fig. 4. As soon as slabs l5and it are laid, joint spaces 26 and the similar joint spaces betweenthe ends of the slabs are filled with hot asphalt which, by reason ofits high temperature, has a tendency to melt the impregnating asphalt inthe pores of the concrete at the edges of the slab. The result is thatthe joint filling asphalt, when cooled and hardened, will have becomesubstantially integrated with the asphalt with which the slabs areimpregnated. There is thus formed a joint that is thoroughly water tightand resistant to frost, acids, alkalies and other such deterioratingagencies. For further details concerning this type of joint, see PatentNo. 1,953,920, granted to me April 10, 1934, on Protected concretestructures.

After laying the three lowermosts course of slabs, I then place the sideslabs which are shaped similar to the bottom slabs 55, except that theyhave peripheral tongues extending along one side and end, and grooveswithin the remaining side and end. Tongue and groove joints 23 areformed between slabs l5 and the top angularly extending edges of theformer having grooves 2 which receive tongues 25 on the lower edges ofslabs 22. The joints at 23 are sealed with asphalt by first fillinggrooves M- with hot asphalt and then placing slabs 22. It may bementioned that the joints between abutting ends of successive side slabs22 will also be of the tongue and i groovetype, and will be filled withhot asphalt after the slabs have been placed, by pouring the joints fromthe top.

Before slabs 26 are positioned, the reenforcing steel is put into place.Slabs 26 are next put in place and held in the positions illustrated bytemporary spreaders, not shown, placed between the upper ends of theslabs to keep them in place while the concrete is being poured. Asphaltfilled tongue and groove joints similar to the previously describedjoints connect slabs 22 and 26 along their adjacent horizontallyextending edges. The end. joints between successive slabs 26 willhowever be similar to the later mentioned joints at 28, see Fig. 4, inorder that they may be poured from above.

All except the top slabs 29 having been placed and the joints cooled,concrete St is now poured into the interior space enclosed by the slabsand around suitable previously placed reenforcement 33!. Preferably theconcrete will be tamped, vibrated or otherwise compacted into the slabform in order to exclude air and to secure the desired denseness. Theconcrete mixture may be proportioned to give great strength when set,and

to have high density withoutsubstantial porosity.

When the space within the slab form has been filled to a point near thetop, slabs 29 are then laid in place and bedded until their top surfaces29a are flush with the beveled top surfaces 23a. of slabs 26.

These top slabs 29 will be tamped firmly in place to compact theconcrete beneath, and then, in order to insure that the joint recesses Iwithin the slabs will be entirely filled with concrete, grout is pouredor forced under a slight pressure into the key recesses through holes 33cast within the slabs. Air and surplus grout are at the same timedisplaced through another set of holes 34, there being, as illustratedin Fig. 5, inlet and outlet holes extending through the slab into eachkey recess. The adjacent edges of slabs 26 and 29 are beveled to formwedge-shaped joint spaces at 35, and the abutting ends of successiveslabs 29 are beveled to form similar joint spaces as indicated at 28 inFig. 4. After the top slabs have become bedded with their key recessescompletely filled with grout, holes 33, 34 and joint spaces 28 and 35are cleaned out, allowed to dry, and then filled with hot asphalt. Afterthe concrete has set for a period, the brace structures l l are removed.

At the same time the intermediate portion of the pile is being castwithin permanent slabs as described, end portions of the pile extendingbeyond the slabs are also cast. As shown in Fig. 3, the driven end 31 ofthe pile is a solid concrete continuation of the concrete core 30enclosed within the slabs, and has a cross sectional configurationconforming to the polygonal outer surface shape of the slab assembly. Asshown in Fig. 4, the end slabs adjacent the driven end of the pile bearagainst shoulders 38 and form with the end 31, continuous smoothsurfaces. If desired, asphalt filled joints may be formed at 38a betweenthe end slabs and the driven end section of the pile. I

In casting the opposite solid concrete end 39 of the pile,longitudinally extending key recesses 40 having undercut sides 4|, seeFig. 8, are formed in the surfaces of the concrete, the lower ends ofthe recesses being closed by inwardly beveled shoulders 42, see Fig. 3.Recesses 40 may be cast by pouring the concrete around correspondinglyshaped form boards which may be withdrawn endwise from the recessesafter the concrete has set sufiiciently to hold its shape. I have notundertaken to illustrate forms to be used in casting the two endportions 3'! and 39 of the pile, since the building of forms to castthese portions of the pile in the shapes illustrated requires no specialskill.

After the concrete has set and hardened, the pile is ready for drivingin an upright position with end section 39 at the top. By reason of thefact that initially the protective slabs are not ap plied to theuppermost section 39 of the pile, the pile driver blows are nottransmitted directly to the slabs, but alone to the concrete core.Although as the pile is being driven, shearing stresses between theconcrete core and the permanent form slabs may be set up due to theinertia of the slabs, any cleavage whatsoever at the joints formed bythe slab key recesses is prevented by the transverse shoulders, forexample undercut shoulders I8 in Fig. 6, bearing against the concretefilling the recesses. In effect, the permanent slab form has becomeintegratedwith the body of the pile, and has substantially the samestrength.

The piles ordinarily will be driven to a depth such that theintermediate section to which the slabs are applied will extend aboveand below the limits of rise and fall of the water level. Ex-

perience has shown that where the piles are driven in sea water beds, itis within these limits that the pile is subjected to greatestdeterioration by reason of the alternate submergence and exposure toair. It is readilyapparent that by reason of the integrated protectiveslab structure and the waterproof joints between the slabs, the concretebody of the pile is rendered entirely immune to attack.

Since the final depth to which a pile will be driven cannot bedefinitely ascertained in advance due to unknown conditions in the soiland formation into which the pile is driven, it is necessary to adjustthe height of the driven pile to suit the level of the structure whichit is to support, either by cutting off or adding to its upper end. Thepresent pile structure lends itself particularly to height adjustmentafter driving, and to final application of slabs in order that the pilemay be protected throughout its entire extent above the water level.When the pile is driven, slabs 43 and H, see Fig. 8, are placed aroundthe top section 39, these slabs having self-contained under-cut keyrecesses 45 and 46 similar to the key recesses lSa in the previouslydescribed permanent form slabs 16. As illustrated, 1

the slab recesses come directly opposite the undercut key recesses 41!cast in the body of the pile, so that concrete poured into the recessforms a double key bonding the slabs to the body. The slabs have tongueand groove joints 4'! along their vertically extending edges, and ifdesired, similar joints may be formed between these slabs and the upperend of the intermediateslab section, and between vertically successiveslabs applied to the top section 40 of the pile.

In applying slabs 43 and 44, all the joints 4? may be filled by pouringhot asphalt into the joint spaces from their upper ends after the slabshave been arranged about the pile as shown in Fig. 8, or the sleeveformed by the slabs may first be made in sections by joining two or moreof the slabs before applying them to the pile. After the joints havehardened, grout is poured into the upper ends of the body key recessesll] and caused to fiow down into and fully occupy the slab key recesses.Upon hardening, the grout forms keys 48 which securely bond the slabs tothe concrete body of the pile.

In cases where it is necessary to extend the pile above the upper end ofsection 4! slabs 43 and M1 may be built up to the desired height as asleeve form, within which additional reenforcement steel may be placedand concrete poured. In this case complete sleeve sections may be formedof the slabs before being placed on the pile, and these sections placedone upon the other, with sealed joints between, until the desired heighthas been reached.

In Fig. 7 I show a protected floor structure supported on the upper endof the pile after the height of the latter has been adjusted aspreviously explained. A concrete beam form comprising a series of sideslabs 50 and bottom slabs 5| is built on a row of piles with the bottomslabs 5| resting upon their upper ends. These beam form slabs aresimilar in all respects to the previously described slabs applied to thepile, both as to waterproof characteristics and shape. The pilereenforcement 52 may be extended up into the beam form, and asphaltfilled tongue and groove joints provided at 53 between the bottom slabs5| and the lower edges of side slab 50. Additional slabs 54 may besuitably supported and joined to slabs 50 by asphalt filled joints at55, to form the bottom protective layer of a concrete floor. After theslabs have been arranged as described, concrete is poured into space 56to form a horizontally extending beam, the fioor 51 being poured at thesame time. In setting, the concrete becomes securely bonded to theslabs, which in turn form an integral continuous protective layer aboutthe beam and the entire underside of the fioor.

In Figs. 9 to 11 I show a variational form of the invention in which theslabs are applied tothe surface of sheet piling composed of individualpiles 58 driven edge to edge and forming a continuous wall. The pilesare precast with tongues 59 and grooves (it which interfit when thepiles are driven in place. The individual piles are also precast withthe view to protecting the surface 6| of the wall most subject todisintegration, as for example because of exposure to sea water, by theapplication and bonding of protective slabs thereto. For this purposethe piles 58 are cast with vertically extending key recesses 62 havingundercut sides and extending continuously within that portion of thepile extent that is to be protected.

The slabs 63 may be applied to the face 6| of the sheet piling wall invarious manners. For example, the lowermost horizontal course 64 of theslabs may be supported in place, the end tongue and groove joints 65filled with hot asphalt, and then the upper courses 56 and 6'! appliedsuccessively, the horizontal tongue and groove joints 68 and thevertical joints 65 being poured as the slab structure is built up to thelevel of the top 58a of the piling. After the several slab courses havebeen placed and the joints allowed to harden, grout is poured or forceddown through key recesses 62 in the pile, completely filling theserecesses and also the key recesses 69 in the slabs. After the groutsets, the slabs will have become bonded and keyed to the surface of thepiling, forming a continuous waterproof protective layer. Ordinarily theslabs need he applied to only a sufficient vertical extent of the pilethat the lower slab course will at all times be submerged beneath thelevel of the water to which the piling is exposed.

Instead of first building up the successive slab courses to the top ofthe piling and then pouring grout to fill the key recesses of all theslabs at once, if found necessary or for any reason desirable, the groutmay be poured into the key recesses after each horizontal slab course islaid. Since in this case the grout will be poured at intervals toshallower depths, a better opportunity may be given to avoid forming airpockets within the recesses, since the air may more readily escape.

After the slabs have been applied to the face of the sheet piling wallas described, a waling may be cast on the top of the piling andprotected by slab courses continuing upwardly from those previouslyapplied to the piling. In casting the waling I first place one or morecourses 10 of slabs on the previously laid courses, and connect theindividual slabs with tongue and groove waterproof joints of thecharacter previously described. These slab courses EB serve as permanentforms against which the concrete for the waling H is poured, othertemporary forms being erected to cast the waling in the shape indicated.

Where it is desired to cast an individual waling to be applied to a wallor sheet piling, this waling can be precast within protective slabs andthen mounted. Thus in Fig. 10, I show a waling l9 placed at or below thelow'water level and attached to the piling by horizontal tie rods 33.The waling is precast by pouring concrete into slabs BI, 82, and 83, thetop slabs 84 being applied last and the enclosed space finally filled bypouring or forcing in grout through apertures in these top slabs, aspreviously described with reference to Fig. 5. A protective closure 35through which the tie rod is to extend, may be formed of smallsize slabsor of a single impregnated concrete tube, and placed in the positionshown before the concrete 86 is poured. Waterproof tongue and groovejoints are formed between the slabs encasing the waling, as shown, andalso at 8? between the lowermost slab 64 and the top slab 84 of thewaling.

Figs. 12 and 13 show a variational form of the invention in which anindividual pile is entirely enclosed within a protective sleeve made upof slabs applied to the pile in essentially the same method as that justdescribed with reference to the sheet piling. In Fig. 13 I show aprecast square concrete pile 12 having longitudinally extending undercutkey recesses 13 formed in each of its four surfaces. Protective slabs Mapplied to the faces of the pile have end key recesses 55 directlyopposite the pile key ways '13, and have asphalt filled tongue andgroove joints at T6 and I'd along their engaging vertically andhorizontally extending edges. The lowermost slabs I la are supported ona shoulder 78 which may be cast integrally with or otherwise fastened tothe pile. As in the forms of the invention shown in Figs. 8 and 11, theslabs "M are bonded to the surface of the pile by grout poured intorecesses 13.

In all the previously described forms of the invention in which theslabs have been applied to driven piles, the latter have been precastwith grout receiving recesses in their surfaces. I may state that it isreadily possible and fully practical to apply the slabs to driven pilesthat have not been specifically cast to provide bonding irregularities,simply by forming such irregularities in the pile surface by the use ofair drills or other suitable implements. The irregularities or groutreceiving spaces so formed need not necessarily take the shape ofundercut key ways such as I have shown in the cast piles, but they maybe of any character or configuration that will enable a secure bond tobe had between the slabs and the pile. As an alternative method ofapplying the slabs to piles that have not had bonding recesses formed intheir surfaces, or to smooth surface piles I may apply coarse wire mesh,reenforcement materials or the like, to the pile, then place the slabsagainst the Wire mesh or reenforcement, and finally pour grout into thespace between the slabs and the pile. In this case the reenforcementacts to bond the grout to the pile, instead of irregularities formed inthe surface of the latter.

I claim:

1. The method that includes, driving a pile, then protecting the surfaceof said pile throughout a predetermined portion of its length byapplying preformed waterproof slabs thereto in contact with saidsurface, both the inner surfaces of the slabs and outer surface of thepile having recesses formed therein, and bonding the slabs to the pilewhile in contact with said surface, by pouring grout into said recesses.

2. The method that includes, driving a pile, and

then protecting the surface of said pile throughout a predeterminedportion of its length by applying preformed waterproof slabs thereto incontact with said surface, both the inner surfaces of the slabs andouter surface of the pile having recesses formed therein, sealing thejoints between said slabs, and then cementing the slabs to the pilewhile in contact with said surface, by pouring grout into said recesses.

3. The method that includes, driving a pile comprising a lower sectionhaving an integral water proof sleeve and an upper unprotected section,and then protecting the surface of said upper section by applyingpreformed waterproof slabs to said surface and in contact therewith sothat the slabs are supported on the upper end of said sleeve, both theinner surfaces of the slabs and outer surface of the pile havingrecesses formed therein, and pouring grout into said recesses to cementthe slabs to the pile while in contact with said surface.

4. The method that includes, driving a pile comprising a lower sectionhaving an integral waterproof sleeve formed of impregnated concreteslabs,

and an upper unprotected section, and then protecting the surface ofsaid upper section by applying preformed waterproof slabs thereto incontact with said surface directly above said sleeve, both the innersurfaces of the slabs and outer surface of the pile having recessesformed therein, sealing the joints between the last mentioned slabs, andpouring grout into said recesses to cement the slabs to the pile whilein contact with said surface.

5: The method that includes, driving a pile comprising a lower sectionhaving an integral water-' proof sleeve and an upper unprotectedsection, and then protecting the surface of said upper section byapplying preformed waterproof slabs thereto in contact with said surfaceand said sleeve, both the inner surfaces of the slabs and outer surfaceof the pile having recesses formed therein, sealing the joints betweenthe last men- 'tioned slabs and between the slabs and the sleeve,

and pouring grout into said spaces with the slabs contacting saidsurface.

JOHN W. B. BLACKMAN.

